package com.yycx.common.utils.file;

import com.yycx.common.base.vo.ZipFileVo;

import java.io.*;
import java.net.URLEncoder;
import java.util.List;
import java.util.zip.ZipEntry;
import java.util.zip.ZipOutputStream;

import javax.servlet.http.HttpServletResponse;

/**
 * 压缩包文件导出
 *
 * @author zyf
 */
public class ZipUtil {
    /**
     * 导出
     *
     * @param response
     * @param zipFiles
     * @param zipName  压缩包名称
     * @return zip文件
     */
    public static void createZipFile(HttpServletResponse response, List<ZipFileVo> zipFiles, String zipName) {
        // 输出响应
        ZipOutputStream zipStream = null;
        response.setContentType("application/x-zip-compressed");
        response.setHeader("Cache-Control", "max-age=0");
        try {
            response.setHeader("Content-Disposition ", "attachment; filename=" + URLEncoder.encode(zipName + ".zip", "UTF-8"));
            //1：定义为输出流
            OutputStream os = response.getOutputStream();
            //2.把输出流给压缩流
            zipStream = new ZipOutputStream(os);
            //3.把file文件，和要修改的名称 循环写入到 FileInputStream 输入流里面
            for (ZipFileVo zipFile : zipFiles) {
                File file = zipFile.getFile();
                compressZip(file, zipStream, zipFile.getFileName());
            }
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            try {
                if (zipStream != null) {
                    zipStream.close();
                }
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    }

    private static void compressZip(File file, ZipOutputStream zipStream, String alias) throws Exception {
        FileInputStream input = null;
        try {
            //3.1.把file文件 写入到 FileInputStream 输入流里面
            input = new FileInputStream(file);
            //3.2.把 FileInputStream 输入流 写入到 byte[] 字节中
            zip(input, zipStream, alias + "." + file.getName().substring(file.getName().lastIndexOf(".") + 1));
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            try {
                if (input != null) {
                    input.close();
                }
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    }

    /**
     * 写入压缩文件
     *
     * @param input
     * @param zipStream
     * @param zipEntryName
     * @throws Exception
     */
    private static void zip(InputStream input, ZipOutputStream zipStream, String zipEntryName) throws Exception {
        //byte[] 字节
        byte[] bytes = null;
        BufferedInputStream bufferStream = null;
        try {
            if (input == null) {
                throw new Exception("获取压缩的数据项失败! 数据项名为：" + zipEntryName);
            }
            // 压缩条目不是具体独立的文件，而是压缩包文件列表中的列表项，称为条目，就像索引一样
            ZipEntry zipEntry = new ZipEntry(zipEntryName);
            // 定位到该压缩条目位置，开始写入文件到压缩包中
            zipStream.putNextEntry(zipEntry);
            // 读写缓冲区
            bytes = new byte[1024 * 5];
            // 输入缓冲流
            bufferStream = new BufferedInputStream(input);
            int read = 0;
            while ((read = bufferStream.read(bytes)) != -1) {
                //压缩输出流写入bytes[] 数据
                zipStream.write(bytes, 0, read);
            }
        } catch (IOException e) {
            e.printStackTrace();
        } finally {
            try {
                if (null != bufferStream)
                    bufferStream.close();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    }

}

